1. Field of the Invention
The present invention is related to a luminous pen with a pair of light emitting diodes under dual mode control.
2. Description of Related Art
We are already familiar with Luminous ball pen, and a variety of patented luminous pens are described in domestic and foreign patent documents. In summary, light emitting diode (LED) is disposed on a top end of the pen shaft emits light for illuminating surrounding environment or for making the pen look interesting and attractive. LED disposed may be disposed near a pen tip portion such it emits light while writing so that when writing in the dark, the surrounding environment is illuminated. Alternatively, the LED may be disposed at a middle portion of the pen shaft to emit light for illuminating the trademark or patterns formed thereon.
Most LEDs switches on or off by pressing buttons on the top end of pen shaft, or LEDs may be turned on or off by rotating upper or lower portion of the pen shaft relative to each other; or being depressed inward of the pen shaft, where a button or key is normally bulged out, to determine whether LED is lit up or not.
Conventional luminous ball pen has some of the following drawbacks.
1. Press button on top of the pen shaft usually must be pressed downward several times to activate LED. For example, to light up LED once, the press button must be pressed downward, at least three times in order to light up LED and vice versa, impel pen nib from a retract position to a written position and vice versa. When two LEDs are disposed in a pen shaft, the press button must be pressed six times to determine light/dim modes of two LEDs, and retract/written positions of pen nib. In other words, one LED may be lit up one time, as the press button is pressed into the top end of pen shaft up to six times. Therefore, how to reduce the number of pressing times of a button is an important issue for improving the convenience of usage of the luminous pen.
2. When a luminous ball pen is not in use, users may unintentionally touch the press button, or rotate the upper or lower shaft, or click the key bulged out from the shaft. As a result, LEDs are being continuously turned on and consume power. Therefore, how to prevent such unintentional turning on of the LEDs is another important issue prevent unnecessary wastage of power.
3. Dual mode luminous ball pen may provide a first LED on top of the pen shaft to illuminate surrounding environment, but no projected images can be presented by the first LED. Therefore, how to increase a projected image function of the first LED is yet another important issue to improve the esthetic appearance of the luminous pen.